Cooperative query answering for RDF

Abstract

The interest of representing data for the Semantic Web has generated standards for expressing knowledge on the Web. RDF, as one of those standards, has become a recommendation of the W3C. Even if it was designed to be human and machine readable (XML encoding, triples, labeled graphs), RDF was not provided with querying and reasoning services. Most work on querying RDF has concentrated on the use of logic programming evaluation techniques and SQL extensions. We take a new look at the problem of querying and reasoning on RDF statements and find that order-sorted feature (OSF) terms apply to this problem because OSF have been tailored for efficiency and their semantics is compatible with the isomorphic representation (triples) of RDF statements. This transformation allows to compute an ordering on resources and thus provide better answering mechanisms when querying RDF. © Springer-Verlag Berlin Heidelberg 2005.